Human Molecular Genetics

Whole-exome sequencing and functional validation reveal a rare missense variant in MMP7 that confers ovarian endometriosis risk

Abstract Prior studies have shown that genetic factors play important roles in ovarian endometriosis. Herein, we first analyzed the whole-exome sequencing data from 158 patients with ovarian endometriosis and 385 local control women without endometriosis. Among which, a rare missense variant in the MMP7 (p.I79T, rs150338402) gene exhibited a significant frequency difference. This rare variant was screened in an additional 1176 patients and 600 control women via direct DNA sequencing. Meanwhile, a total of 38 available clinical characteristics were collected. Our results showed 45 out of 1334 (3.37%) patients, while 15 out of 985 control women (1.52%) (P = 0.0076) harbored this rare variant, respectively. This rare variant was associated with clinical features such as follicle-stimulating hormone (Padj = 0.0342), luteinizing hormone (Padj = 0.0038), progesterone (Padj = 1.4e−7), testosterone (Padj = 0.0923), total bilirubin (Padj = 0.0699), carcinoembryonic antigen (Padj = 0.0665) and squamous cell carcinoma antigen (Padj = 0.0817), respectively. Functional assays showed that this rare variant could promote cell migration, invasion, epithelial–mesenchymal transition (EMT) and increase the proteolytic protein activity of MMP7, implicating that the increased capacities of cell invasion, migration and EMT might be mediated by enhanced proteolytic activity of MMP7 mutant. These results showed that the MMP7 rare missense variant (p.I79T) played important roles in the pathogenesis of ovarian endometriosis. In conclusion, we identified, for the first time, a significantly enriched MMP7 rare variant in ovarian endometriosis; this rare variant was closely associated with certain clinical features in ovarian endometriosis; thus, it could be a promising early diagnostic biomarker for this disease.

Mesenchymal stem cell-derived extracellular vesicles alleviate cervical cancer by delivering microRNA-331-3p to reduce LIM zinc finger domain containing 2 methylation in tumor cells

Abstract The aim of this study is to investigate if extracellular vesicles (EVs) from bone marrow mesenchymal stem cells (BMSCs) deliver microRNA (miR)-331-3p to regulate LIM zinc finger domain containing 2 (LIMS2) methylation in cervical cancer cells. Cervical cancer cells were incubated with EVs from BMSCs with altered expression of miR-331-3p, DNA methyltransferase 3 alpha (DNMT3A) or/and LIMS2 and then subjected to 5-ethynyl-2′-deoxyuridine, Transwell, flow cytometry and western blotting analyses. Dual-luciferase reporter assay was conducted to verify the binding between miR-331-3p and DNMT3A. A xenograft model was established to evaluate the effect of BMSC-derived EV-miR-331-3p on cervical tumor growth. miR-331-3p was lowly and DNMT3A was highly expressed in cervical cancer. BMSC-derived EVs delivered miR-331-3p to control the behaviors of cervical cancer cells. miR-331-3p inhibited the expression of DNMT3A by binding DNMT3A mRNA. DNMT3A promoted LIMS2 methylation and reduced the expression of LIMS2. Overexpression of DNMT3A or silencing of LIMS2 in BMSCs counteracted the tumor suppressive effects of miR-331-3p. BMSC-derived EV-miR-331-3p also inhibited the growth of cervical tumors in vivo. BMSC-derived EVs alleviate cervical cancer partially by delivering miR-331-3p to reduce DNMT3A-dependent LIMS2 methylation in tumor cells.

Genome-wide association study and functional follow-up identify 14q12 as a candidate risk locus for cervical cancer

Abstract Cervical cancer is among the leading causes of cancer-related death in females worldwide. Infection by human papillomavirus (HPV) is an established risk factor for cancer development. However, genetic factors contributing to disease risk remain largely unknown. We report on a genome-wide association study (GWAS) on 375 German cervical cancer patients and 866 healthy controls, followed by a replication study comprising 658 patients with invasive cervical cancer, 1361 with cervical dysplasia and 841 healthy controls. Functional validation was performed for the top GWAS variant on chromosome 14q12 (rs225902, close to PRKD1). After bioinformatic annotation and in silico predictions, we performed transcript analysis in a cervical tissue series of 317 samples and demonstrate rs225902 as an expression quantitative trait locus (eQTL) for FOXG1 and two tightly co-regulated long non-coding RNAs at this genomic region, CTD-2251F13 (lnc-PRKD1-1) and CTD-2503I6 (lnc-FOXG1-6). We also show allele-specific effects of the 14q12 variants via luciferase assays. We propose a combined effect of genotype, HPV status and gene expression at this locus on cervical cancer progression. Taken together, this work uncovers a potential candidate locus with regulatory functions and contributes to the understanding of genetic susceptibility to cervical cancer.

New insights into tumor microenvironment and HPV integrations in cervical cancer pathogenesis revealed by single-cell transcriptome data

Abstract HPV infection is common among women and can result in serious illnesses. This research utilizes single-cell RNA-sequencing (scRNA-seq) to study the connection between cellular heterogeneity and HPV integrations in cervical histopathology. scRNA-seq was used to examine heterogeneity among normal patients and those in three disease stages: high-grade squamous intraepithelial lesions (HSIL), microinvasive carcinoma (MIC), and cervical squamous epithelium carcinoma cancer (CSCC) tissues. A method was developed to identify HPV integration events from scRNA-seq data. Our results indicated an increase in squamous epithelial cells and a decrease in columnar epithelial cells as the disease progressed from normal to CSCC. We discovered HPV genes that were differentially expressed across normal patients and those in the three disease stages. Notably, HPV integration events were more common in squamous epithelial cells at the single-cell level. The ratio of HPV-integrated cells increased as the disease progressed from normal tissue to CSCC, eventually stabilizing. Several genes, such as EGR1, S100A11, S100A8, KRT5, RPL34, ATP1B1, RPS4X and EEF2, were frequently integrated by HPV across patients. In contrast, genes like PAN3, BABAM2, SPEN, TCIM-SIRLNT, TEX41-PABPC1P2 and KCNV1-LINC01608 showed frequent integration events across cells. KRT5, ATP1B1, RPS4X, PAN3 and SPEN were novel recurrent HPV-integrated genes we observed at the patient or cell level in this study. Additionally, we found that HPV genes from various HPV types exhibited integration preferences in various samples and disease stages. This provides a valuable insight into the mechanism of HPV-induced cervical cancer from a single-cell standpoint, highlighting its clinical relevance.